Evaluating the cosine of an angle using coterminal angles

The video tutorial explains angle measurement, focusing on the concept of pi and how it relates to wrapping a circle. It introduces coterminal angles and demonstrates how to simplify angle measurements by adding or subtracting 2π. The tutorial also covers the unit circle, highlighting major points and their coordinates, and explains how to reflect these points across quadrants.

What is the significance of π in relation to a circle?

• It is the circumference of the circle.

• It represents the diameter of the circle.

• It is the area of the circle.

• It is the number of times the radius can wrap around the circle.

How can you find coterminal angles?

• By converting the angle to degrees.

• By multiplying the angle by 2π.

• By adding or subtracting 2π from the angle.

• By dividing the angle by 2π.

What are the coordinates of the point on the unit circle at 30 degrees?

• (sqrt(3)/2, 1/2)

• (0, 1)

• (1, 0)

• (1/2, sqrt(3)/2)

Which angle corresponds to the coordinates (sqrt(2)/2, sqrt(2)/2) on the unit circle?

• 30 degrees

• 45 degrees

• 60 degrees

• 90 degrees

How do you determine the cosine of an angle using the unit circle?

• By finding the y-coordinate of the point.

• By finding the angle in degrees.

• By finding the x-coordinate of the point.

• By finding the distance from the origin.

What happens to the coordinates of a point when it is reflected from the first quadrant to the third quadrant?

• Both coordinates become negative.

• The y-coordinate becomes negative.

• Both coordinates become positive.

• The x-coordinate becomes negative.

What is the cosine of an angle with coordinates (-1/2, -sqrt(3)/2) on the unit circle?

• sqrt(3)/2

• -sqrt(3)/2

• 1/2

• -1/2